Certain motor vehicles that transport people in substantial numbers at one time, such as school busses, are required by law and/or regulation to comply with certain requirements related to the well-being of the people they transport, school pupils in the case of school busses. A typical school bus has a front entrance/exit door at a side of the vehicle opposite the driver's seat, and a center aisle running from front to rear with a row of seats along each side of the aisle.
As a school bus is preparing to stop to pick up or drop off pupils at various locations along a route, it gives certain signals to other vehicles in the immediate vicinity as an indication that it is coming to a stop for a pick-up. The driver may operate one or more switches to begin flashing certain exterior lamps and/or deploy stop signs at the sides of the bus, or such signals may be issued automatically in one way or another based on conditions indicating that the bus is about to stop for a pick-up or drop-off.
Once the bus has been brought to a complete stop, the front entrance/exit door is opened to allow pupils to board or exit the bus. After the pupils have entered and seated themselves, or alternatively exited, the door is closed. After that, the flashing lamps are extinguished, the deployed stop signs are retracted, and the bus proceeds to the next stop.
Upon the last pupil or pupils having been dropped off, the bus typically proceeds to its final destination which may be on school premises or in a parking yard for school busses not necessarily on the premises of any school.
A number of incidents have been publicly documented where one or more pupils have been left inside a bus after the bus has been parked and the driver has left. These are situations that obviously should not have occurred, but for whatever reason or reasons, actually did.
In efforts to minimize the risk that such incidents might occur in the future, it has been proposed to equip the electrical systems of school buses with systems for alerting responsible persons, chiefly the bus driver, to walk to the rear of the bus at the end of each trip during which pupils have been transported to make sure that none remain inside. Such systems typically rely on the manual actuation of a device near the rear of the bus as an indication that a responsible person has in fact walked to the rear of the bus.
Upon the bus being parked at the end of a trip, a typical system will give an alarm of some sort to alert the driver and possibly other individuals in the immediately vicinity of the need to check the bus for any remaining pupils. If the device at the rear of the bus continues not to be manually actuated within some interval of time after the bus has been parked and the motor shut off, the alarm will continue. In some systems, the driver is given the option of delaying the alarm for a limited time after the expiration of which the failure to have actuated the device at the rear of the bus will cause the alarm to be given.
U.S. Pat. Nos. 5,128,651, 5,874,891, 6,107,915, and 6,259,358 B1 and U.S. Patent Application Publication No. 2003/0030550 A1 describe various systems that require manual actuation of a device at the rear of a bus as an indicator that a responsible person has walked to the rear to check for any persons remaining on the bus after they should have de-boarded. They disclose various conditions for arming and disarming the systems, various conditions for triggering alarms, and various conditions for allowing alarms to be turned off.
In some systems like that of U.S. Pat. No. 5,128,651, operation of the vehicle's ignition switch to OFF position is effective to give an alarm. U.S. Pat. No. 5,128,651 allows for the ignition switch to be turned from OFF to ON to silence an alarm without having to manually operate a device at the rear of the bus, but when the ignition switch is again turned to OFF, the alarm will be given and can be shut off only by manual actuation of the device at the rear of the bus.
The system of U.S. Pat. No. 5,874,891 allows the driver to deactivate the alarm system with the engine still running (ignition switch in ON) by walking to the rear of the bus and then manually actuating the device at the rear. While that is alleged to be a convenience to the driver, U.S. Pat. No. 5,128,651 seems to consider that possibility undesirable because it would allow any pupil, either on the pupil's own initiative or on instruction from the driver, to deactivate the system by manually operating the device at the rear while the driver remains driving the bus.